Neither wins outright: AI21: Jamba Large 1.7 is the pick when you need to fit long inputs in one request, Moondream: Moondream 3.1 when cost matters at scale.
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
Workload (per month)
AI21: Jamba Large 1.7
Moondream: Moondream 3.1
Difference
Customer-support chatbot
50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens)
$310
$72.50
Moondream: Moondream 3.1 saves $238
RAG search over documents
20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens)
$320
$61.00
Moondream: Moondream 3.1 saves $259
Coding / tool-using agent
2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens)
$336
Doesn't fit context
—
Batch summarisation
10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens)
$208
$39.00
Moondream: Moondream 3.1 saves $169
Long-document analysis
500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens)
$108
Doesn't fit context
—
Capabilities side by side
Capability
AI21: Jamba Large 1.7
Moondream: Moondream 3.1
What it lets you do
Tool / function calling
✓ Yes
—
call your APIs and run agent loops
Structured output (JSON schema)
✓ Yes
—
return JSON that validates against your schema
Reasoning / thinking mode
—
✓ Yes
spend extra tokens thinking before answering hard problems
Image input
—
✓ Yes
read screenshots, charts and scanned pages
Audio input
—
—
take speech or audio directly
File / PDF input
—
—
accept documents without your own parsing step
Image output
—
—
generate images, not just text
Built-in web search
—
—
answer from live web results
Seed (reproducible sampling)
—
—
repeat a generation for tests and evals
Log-probabilities
—
—
read token confidence for classification and scoring
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
AI21: Jamba Large 1.7: price unchanged since we started tracking it on 2026-03-10.
Moondream: Moondream 3.1: price unchanged since we started tracking it on 2026-10-16.
Which should you choose?
Choose AI21: Jamba Large 1.7 if…
you need to fit long inputs in one request — 256K tokens is roughly 384 pages, against 48
you need tool / function calling — to call your APIs and run agent loops; Moondream: Moondream 3.1 does not advertise it
you need structured output (JSON schema) — to return JSON that validates against your schema; Moondream: Moondream 3.1 does not advertise it
Choose Moondream: Moondream 3.1 if…
cost matters at scale — it is 76% cheaper on a typical 3:1 input/output mix ($72.50 vs $310 a month for 50,000 support chats)
you need reasoning / thinking mode — to spend extra tokens thinking before answering hard problems; AI21: Jamba Large 1.7 does not advertise it
you need image input — to read screenshots, charts and scanned pages; AI21: Jamba Large 1.7 does not advertise it
you want the newer model — released 2026-10-15, 14 months after the other
Frequently asked questions
Is AI21: Jamba Large 1.7 better than Moondream: Moondream 3.1?
Neither wins outright: AI21: Jamba Large 1.7 is the pick when you need to fit long inputs in one request, Moondream: Moondream 3.1 when cost matters at scale. In short: AI21: Jamba Large 1.7 when you need to fit long inputs in one request, you need tool / function calling, you need structured output (JSON schema); Moondream: Moondream 3.1 when cost matters at scale, you need reasoning / thinking mode, you need image input, you want the newer model.
Which is cheaper, AI21: Jamba Large 1.7 or Moondream: Moondream 3.1?
Moondream: Moondream 3.1 is cheaper: $0.85 vs $3.50 per 1M tokens at a typical 3:1 input/output mix, 76% less. For 50,000 support conversations a month that is $72.50 against $310.
How much do AI21: Jamba Large 1.7 and Moondream: Moondream 3.1 cost per million tokens?
AI21: Jamba Large 1.7 costs $2.00 per 1M input tokens and $8.00 per 1M output tokens; Moondream: Moondream 3.1 costs $0.30 input and $2.50 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, AI21: Jamba Large 1.7 or Moondream: Moondream 3.1?
AI21: Jamba Large 1.7: 256K tokens, about 384 pages, against 32K (about 48 pages) for Moondream: Moondream 3.1.
Do AI21: Jamba Large 1.7 and Moondream: Moondream 3.1 support function calling and JSON output?
Tool calling — AI21: Jamba Large 1.7: yes, Moondream: Moondream 3.1: not advertised. JSON-schema structured output — AI21: Jamba Large 1.7: yes, Moondream: Moondream 3.1: not advertised.
Can AI21: Jamba Large 1.7 or Moondream: Moondream 3.1 read images?
Only Moondream: Moondream 3.1 accepts image input; AI21: Jamba Large 1.7 is text-only for input.
Is AI21: Jamba Large 1.7 or Moondream: Moondream 3.1 free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of AI21: Jamba Large 1.7 and Moondream: Moondream 3.1?
AI21: Jamba Large 1.7 can write up to 4K tokens (about 3,100 words) per response; Moondream: Moondream 3.1 up to 4K (about 3,100 words).
When were AI21: Jamba Large 1.7 and Moondream: Moondream 3.1 released?
AI21: Jamba Large 1.7 was listed on 2025-08-08; Moondream: Moondream 3.1 on 2026-10-15.
Jamba Large 1.7 is the latest model in the Jamba open family, offering improvements in grounding, instruction-following, and overall efficiency. Built on a hybrid SSM-Transformer architecture with a 256K context...
Moondream 3.1 is a vision-language model from Moondream, the successor to Moondream 3 Preview, with 9B total parameters and 2B active (mixture-of-experts). It handles visual question answering, captioning, OCR, and...